This invention relates to composite hook and loop fasteners, methods of their manufacture and products containing them.
A typical composite hook and loop fastener is produced by taking preformed hook and loop material and overlapping and attaching the two materials together along their edge margins or by totally overlapping one on top of the other. The attaching is usually done by ultrasonic welding, thermal fusing or an adhesive bond. This step of attaching preformed hook and loop material to form the composite fastener adds additional cost to the manufacturing process. Hook and loop materials may also be laminated inside during the formation of the hook component.
One particular application for an improved composite fastener, discussed in more detail below, is as a wrap tie for closing bags. An economical bag tie commonly used in retail stores comprises a wire covered with paper. The wire tie is wrapped around an open end of a bag and the ends of the wire are twisted together to close the bag. Another common type of a bag tie is a clip tie that consists of a piece of plastic with an opening. A gathered open end of the bag is pushed through the side of the opening to close the bag. Other closures include strings and tapes and closing arrangements that employ adhesives or removably engageable elements.
The wire ties and clip ties are often used in retail stores where items such as bakery products, fresh produce, dry goods, nails, etc. are placed in a bag and sold by eight or number. The consumer usually scores these products in the bags. The ties may be opened and closed several times before the bag is emptied. There is a need for low-cost dependable repeated-use closures for this and any other applications.
A composite hook and loop fastener in the form of an elongated strip includes a loop component, a hook component permanently affixed to the loop component, and a backing layer disposed on a face of the wrap tie in a discrete region. The backing layer is used for permanent attachment of the wrap tie to a supporting surface. One end of the loop component is available for encircling an object to be wrapped and engaging the fastener elements of the hook component. The loop component has a self-supporting web of entangled fibers, the fibers forming both a sheet-form body and hook-engageable, free-standing loops extending from at least one surface of the body, and the hook component has fastener elements extending from a common base.
In general, in one aspect, the invention provides a wrap tie in the form of an elongated strip. The wrap tie has an elongated loop component having a web of fibers forming both a sheet-form body and hook-engageable loops extending from at least one surface of the body, a hook component permanently affixed to a first end of the loop component, the hook component comprising a base of synthetic resin and an array of loop-engageable fastener elements integrally molded with and extending from a first surface of the base, and a backing layer permanently affixed to a second surface of the base opposite the fastener elements, for permanent attachment of the wrap tie to a supporting surface. A second end of the loop component is available for encircling an object to be wrapped and engaging the fastener elements of the hook component.
Implementations of this aspect of the invention may include one or more of the following features. The web of the loop component may be non-woven and specifically a needled non-woven. The non-woven needled web may weight less than about 2 ounces per square yard (68 grams per square meter). The non-woven web may be in a stretched, stabilized state. The loops of the loop component may extend from loop structures, and at least some of the loop structures may each have a common, elongated trunk portion extending from the web from an associated knot and multiple loops extending from the trunk portion. The loop component may have an edge margin encapsulated in resin of the hook component, and a remainder free of hook component resin. The edge margin may be about 10% of the area of the loop component. The loop component may have an entire face encapsulated in resin of the hook component. The loop component may have two broad, opposite sides, and loops may extend from both sides. The hook component may be shorter than the loop component, as measured along the wrap tie, and the backing layer may overlap longitudinally the hook component and may be disposed on a side of the wrap tie opposite the fastener elements. The fastener elements of the hook component may be hook- or mushroom-shaped. The hook component may be disposed at one end of the elongated wrap tie, and the hook-shaped fastener elements may extend toward the other end of the wrap tie. The base of the hook component may include an integral extension void of fastener elements, for overlapping the loop component and for face-to-face attachment. The backing layer may be a pressure sensitive adhesive or a synthetic resin. A removable release liner may cover the pressure sensitive adhesive layer. The release liner may overlap longitudinally the loop component such that a portion of the release liner is exposed for grasping.
According to another aspect of the invention, a wrap tie has an elongated hook component having a base of synthetic resin and an array of fastener elements extending from a first surface of the base, a loop component permanently affixed to a first end of the hook component, the loop component having a web of fibers forming both a sheet-form body and hook-engageable loops extending from at least a first surface of the body, and a backing layer permanently affixed to a second surface of the body of loop component for permanent attachment of the wrap tie to a supporting surface. A second end of the hook component is available for encircling an object to be wrapped and engaging the hook-engageable loops of the loop component. The hook component may be in a stretched state.
According to another aspect of the invention, a bag has an open end and an elongated, strip-form wrap tie according to this invention, permanently affixed to an outer surface of the bag for closing the open end. The wrap tie is permanently bonded to the outer surface of the bag in a discrete region along the length of the wrap tie. One end of the loop component is available for encircling the open end of the bag to secure the bag in a closed state. The wrap tie may be permanently affixed to the bag by a pressure sensitive adhesive layer or a synthetic resin. The bag may be made of synthetic resin or paper.
According to another aspect of the invention a sheet-form composite touch fastener includes a loop component having a self-supporting non-woven web of entangled fibers, the fibers forming both a sheet-form web body and hook-engageable free-standing loops extending from at least one surface of the web body, and a hook component having a base of synthetic resin to which loop-engageable hooks are integrally molded. The resin of the hook component extends at least partially underneath the loop component and encapsulates fibers of the web body of the loop component.
Implementations of this aspect of the invention may include one or more of the following features. The loop component may have an edge margin encapsulated in resin of the hook component, and a remainder free of hook component resin. The edge margin may be about 10% of the area of the loop component. The loop component may have an entire face encapsulated in resin of the hook component. The loops of the loop component may extend from a common side of the sheet-form touch fastener. The loops of the loop component may be arranged on a side of the sheet-form composite touch fastener opposite to the hooks of the hook component. The fibers of the loop component may be encapsulated in the resin of the hook component and the loop component may comprise regions which are more encapsulated by resin than other regions.
According to another aspect of the invention a sheet-form composite touch fastener includes a sheet-form loop component having a web of fibers forming both a sheet-form web body and hook-engageable loops extending from at least one surface of the web body and a sheet-form hook component comprising a base of synthetic resin to which loop-engageable hooks are integrally molded. One edge region of the hook component is permanently attached to a first edge of the loop component and fibers of the first edge of the loop component are encapsulated by resin of said edge region of the hook component. The loop component has a second edge, opposite said first edge, substantially free of resin of the hook material.
According to another aspect of the invention a method is provided for manufacturing the elongated, strip-form wrap ties of this invention. The method includes the following steps: Provide a longitudinally continuous sheet of a loop material of finite width, the loop material having loops extending from at least a first surface. Permanently bond a longitudinally continuous strip of plastic hook material to the loop material to form a laminate, with the hook material at least partially overlapping the loop material widthwise and having a width significantly less than the width of the loop material, the hook material having a strip-form base and fastener elements integrally molded with and extending from the strip-form base. Apply pressure sensitive adhesive to a predetermined region of a side of the laminate opposite the fastener elements. Cut the laminate to form the wrap ties, each wrap tie having a portion of the loop material, a portion of the hook material, and a layer of the adhesive.
Implementations of this aspect of the invention may have one or more of the following features. For a wrap tie that has a removable release liner covering the layer of adhesive, the method further includes, before the step of cutting, applying a longitudinally continuous release liner to the laminate to cover the adhesive. The cutting at least perforates the loop material and the base of the hook material to define longitudinal edges of the individual wrap ties, and leaves the release liner longitudinally continuous. The cut wrap ties may be spooled upon the continuous release liner for subsequent separation. The hook material may be bonded to the loop material by ultrasonic welding, thermal welding, or pressure sensitive adhesive. The step of bonding may also include continuously feeding the loop material through a nip defined between a rotating mold roll and a pressure roll, the rotating mold roll defining a multiplicity of fixed cavities about its periphery for molding the fastener elements of the hook material, while continuously introducing molten resin to the mold roll under conditions which cause the resin to fill the cavities of the mold roll and form the hook material, such that pressure in the nit bonds the loop material to the hook material. The molten resin may be introduced to the mold roll in multiple, discrete regions along the roll, thereby forming multiple, parallel strips of hook material laminated to the loop material. After the bonding step and before the cutting step, the laminate is slit longitudinally into multiple, longitudinally continuous bands, each band including both hook material, loop material and adhesive. The loop material may be fed through the nip in the form of multiple parallel strips, while forming the hook material to fill gaps between adjacent strips of hook material in the nip.
According to another aspect of the invention a method is provided for manufacturing the elongated strip-form wrap ties of this invention. The method includes the following steps: Provide a longitudinally continuous sheet of a loop material of finite width, the loop material having loops extending from at least a first surface of the loop material. Provide a longitudinally continuous strip of plastic hook material, the hook material having a width significantly less than the width of the loop material, the hook material having a first surface with fastener elements integrally molded with and extending from the first surface, and a second surface, opposite the first surface, having a layer of pressure sensitive adhesive. Bond the hook material and loop material along their length, with the loop material overlapping a longitudinal edge of the hook material and leaving the layer of adhesive uncovered by loop material. Cut the laminate to form the wrap ties, each wrap tie having a portion of the loop material, a portion of the hook material, and a layer of the adhesive.
According to yet another aspect of the invention a method is provided for manufacturing a sheet-form composite touch fastener. The method includes the following steps: Provide a longitudinally continuous sheet of a loop material of finite width, the loop material having a self-supporting non-woven web of entangled fibers, the fibers forming both a sheet-form web body and hook-engageable free-standing loops extending from at least one surface of the web body, said loop material having a substantially constant fiber density across its width. Permanently bond a longitudinally continuous strip of plastic hook material to the loop material to form a laminate, the hook material having a strip-form base of synthetic resin with fastener elements integrally molded with and extending therefrom and wherein said synthetic resin of the base of the hook component extends at least partially underneath the loop component and encapsulates fibers of said web body of the loop component. Cut the laminate to form the composite touch fasteners, each composite touch fastener having a portion of said loop material, and a portion of said hook material.
According to yet another aspect of the invention an apparatus is provided for manufacturing the elongated, strip-form wrap ties of this invention. The apparatus includes a cooled, rotating forming roll defining a plurality of inwardly extending, fixed fastener element cavities at its periphery; a pressure roll positioned to cooperate with the forming roll to define a nip, the pressure roll having an outer surface for supporting a continuous sheet of a loop material fed into the nip; and an extrusion nozzle positioned to direct a continuous flow of molten resin toward the forming roll under conditions which cause the resin to fill the fastener element cavities and to form a continuous layer of resin against the forming roll, such that the layer of resin is bonded to the loop material by pressure in the nip, to form a laminate. The apparatus further includes an applicator arranged to apply a longitudinally continuous layer of pressure sensitive adhesive, to a discrete region of a side of the laminate opposite the fastener elements; a guide arranged to direct a longitudinally continuous release liner to cover the applied layer of adhesive; and a blade arranged to cut in a transverse direction across the laminate to form individual wrap ties.
According to yet another aspect of the invention a method is provided for releasably securing a container in a closed state. The method includes providing a wrap tie according to this invention; permanently adhering the wrap tie to a surface of the container; wrapping one end of the loop component about the container; and engaging the fastener elements of the hook component with the loops of the loop component to retain the container in a closed state.
Among the advantages of the invention may be one or more of the following. The wrap-tie of this invention does not have any sharp or metal parts, which may cut the bag when they become exposed, pose injury risk for the consumer or oxidize and thus contaminate the bag and its contents. There is no preferred direction or need to twist the wrap tie, thus making it easy to open and close the bag opening. Further the wrap tie of this invention can be pre-attached to a bag automatically or can be dispensed from a wrap tie dispenser for manual attachment to a bag. The very low thickness and stiffness of both the non-woven loop material and the hook material, along with its low cost and good closure performance, make the wrap tie a particularly useful component of many products.
Other features and advantages of the invention will be apparent from the following description of embodiments, and from the claims.